Your pp(pathetic partner) has done so much more than cheat, he has endangered your health and the health of your baby. On this board there is a post where the OP has to deal with recurring infection of genital herpes, thanks to her pp cheating on her. This post painfully illustrates the risk your pp took when cheating on his pregnant partner.. Herpes can be passed onto your unborn child. He was playing Russian Roulette every single time he had sex with you. I am betting that you haven't had any std checks recently, I strongly advise you to contact your midwife and advise her that your pp has been cheating on you. If there are checks they can't do now, it can be pencilled in for post partum.
I'm sorry but saying that your pp hasn't cheated on your child is utter nonsense! You have been planning a family for a long time, talking about your future, he cheated on his family, that includes his child.My dh has said he could never cheat, that to do so would be betraying not just me but our children too. If pp wants to put it somewhere else, he should have the decency to end things first. He and OW are only sorry that they were caught, ow is trying to control damage, so that you won't tell her husband (who deserves to know that his wife has been messing about and putting his sexual health at risk).
OP you deserve better than a selfish, irresponsible cheat, who didn't care a bit about the dangers he was exposing you a n d your unborn child to. I seriously would be ending things and considering whether you want him to have parental responsibility to your baby. I am not saying to deny access, on the contrary I agree that every child has the right to their father (not including nasty abusive assholes) however you need to think about your options/ your rights and implications for the future. I would think twice about having him present at the birth, you need calm/ quiet and love and trust from your birth partner. Do you have family/ friends who can help you through this rough time?
Please dont think that your baby arriving will make things better. a baby is like a small nuclear bomb going off in even the strongest relationships, if there are any cracks (which you have actually got huge craters) in your relationship, a baby will magnify them x 10!!!!! If he has cheated on you pre pregnancy, when you had time to look your best and wear make-up, how vulnerable will you feel post partum, when your body has changed, you haven't had a chance to shower and you are covered in baby sick and breast milk? You want a husband who will tell you you look beautiful, run you a bath and make you both dinner. Not to be asking where have you been, why was your phone off, were you with HER Again?
I would be asking myself if i could ever trust him again. You have the chance to move on and meet someone who is not going to cheat you.